I think all this focus on Andrew is obscuring the very real problem of human trafficking of vulnerable girls (which is on the rise even in Canada, thanks to the Internet).
As Osipi has said a few times, whatever role Andrew played in this whole mess, it was a small part (if at all) in a large web of shady characters. Yet because of who he is, the media and U.S. attorneys are focusing solely on him.
I don't think all this attention on Andrew is going to help women get justice. I saw a tweet by Virginia Roberts Guiffre that said "Tick Tock Andy, time's up," or some such thing. I haven't been a victim of abuse myself so my opinion might not count for much, but something sounds off about that tweet. It doesn't sound like it's coming from a victim seeking justice. It sounds malicious.
Victims of human trafficking deserve better than the way this case is playing out in the media. Particularly, shouldn't the focus be on Ghislaine Maxwell? She probably knows more than anyone else.
Andrew might be protecting her; he might not want to testify in case he incriminates her. Or he might not want to testify because he really is lying about having sex with Virginia. But even IF he does speak to the American FBI (which as other posters have explained is unlikely), I don't think he is ever going to say he knew Virginia was being trafficked. And if he didn't know, no one can really prove he did anything criminal at all. I don't know much about American (or British) law, but it strikes me as being somewhat like purchasing stolen goods. If the person who bought them knew they were stolen, he's in the wrong. If he didn't know, he's innocent of any crime. If Andrew knew Virginia was being trafficked, he committed a crime, but if he genuinely thought she was a willing 17 year-old girl, his actions were creepy, age-inappropriate, but not criminally wrong.